1. Field of the Invention
The present invention relates to a mobile communication device, e.g., a cellular phone, and to a mobile communication system using the mobile communication device. More specifically, the present invention relates to a mobile communication device having an automatic transmission function when the mobile communication device deviates from a predetermined activity range. Moreover, the present invention relates to a mobile communication system having an automatic transmission function when a mobile communication device deviates from a predetermined activity range.
2. Description of the Related Art
A location information system using a cellular phone is described in Japanese Laid-Open Patent Application Heisei 8-9450. In the location information system, a terminal device moving between base stations receives a signal transmitted from the base stations and outputs a location information signal indicating the reception thereof, thereby registering the location information signal into a common database. When a search requester searches for the terminal device, the location information of the terminal device is read from the common database and is sent to the search requester.
In the location information system, the search requester must initiate the search request when he/she desires to know the location information of the terminal device. In addition, since the location information of the terminal device is read after the search request is received from the search requester, it takes time to obtain the location information of the terminal device. When a terminal device is lost or stolen or the owner of the terminal device is missing or kidnapped, a delay in obtaining the location information is an important problem.